27709

Appears in sequences

• Initial term of n-th row of triangle in A079784.at n=10A079781
• Least x = a(n) such that sum of common prime divisors (without multiplicity) of sigma(x) and phi(x) equals n, or 0 if such number (apparently) does not exist.at n=25A082056
• Number of permutations of length n which avoid the patterns 2413, 3421, 4123.at n=9A116828
• Number of ways to place zero or more nonadjacent 1,0 2,0 2,1 2,2 3,0 polyhexes in any orientation on a planar nXnXn triangular grid.at n=6A155230
• Number of n X n 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 4,4,0,2,1 for x=0,1,2,3,4.at n=4A197301
• Number of nX5 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 4,4,0,2,1 for x=0,1,2,3,4.at n=4A197304
• T(n,k)=Number of nXk 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 4,4,0,2,1 for x=0,1,2,3,4.at n=40A197307
• Number of subsets of {1..n} whose sum of squares of elements is a square.at n=21A336815
• Number of partitions p of n such that 5*min(p) is a part of p.at n=43A361459